Rounding numbers to make grid snapping?

Help and Feedback Scripting Support
#1

I want to have a building system for building walls and floors and things, but I don’t know how to round to numbers like 4 to make things snap to a grid. How do I do this specific thing?

#3

Maybe this can be of use. It’s a quick forking of mine. This is only reliable for a grid system that has the same grid size. (Like Minecraft or Roblox Islands)

function PositionToGrid(initialValue,step)
local roundedValue = math.floor(initialValue/step)*step
return roundedValue
end

function BlockPosition(BlockName, BlockCFrame, BlockSize, MouseHitPosition)
return PositionToGrid(MouseHitPosition.X+(BlockSize.Y/2), BlockSize.Y), PositionToGrid(MouseHitPosition.Y+(BlockSize.Y/2), BlockSize.Y), PositionToGrid(MouseHitPosition.Z+(BlockSize.Y/2), BlockSize.Y) – The reason for that we use BlockSize.Y all the way through, is because we have a Hitbox/BorderBlock that fills out the whole area of the model/block. (And it will be same length on all axes)
end

DummyBlock:PivotTo(CFrame.new(BlockPosition(BlockName, BlockCFrame, BlockSize, MouseHitPosition))) --The reason for all the Block values is seperated, is due to my serverside validation check aswell. :slight_smile:

#4

Why not use math.round(initialValue) instead of math.floor(initialValue/step)*step

1 Like
#5

Hi! That single line of code is forked.

When I take a closer look at it, it might have something to do with, that the *step doesn’t get rounded, but the rest does. :slight_smile:

#6

Yes, but if you imagine you are using a 10x10 grid.
math.floor(1/10) or (9/10) will equal 0 either way.
math.round(1/10) is 0, but math.round(9/10) is 1.

1 Like
#7

I’m not sure it goes for grids with decimals.

#8

I hate to revive this thread, but I agree with @Scottifly here.

“Flooring” always pushes numbers down, like how the flooring of a house will always be on the bottom.
“Ceiling” always pushes numbers up, like how the ceiling of a house is always on the top.

Rounding can put numbers to the top or bottom, whichever is closest.
Flooring or ceiling grids will never feel (especially for a placement system) as nice as rounding them.

1 Like
#9

Correct, math.round is better for grid placement. At least when someone stumbles upon this thread again, they will know to go with math.round over math.floor / math.ceiling